Refrigerants recently used, for example, for air conditioners, refrigerating devices, and refrigerators are mixtures of fluorinated hydrocarbons that contain no chlorine in their molecular structures, such as difluoromethane (CH2F2, R32, boiling point: −52° C.), pentafluoroethane (CF3CHF2, R125, boiling point: −48° C.), 1,1,1-trifluoroethane (CF3CH3, R143a, boiling point: −47° C.), 1,1,1,2-tetrafluoroethane (CF3CH2F, R134a, boiling point: −26° C.), and 1,1-difluoroethane (CHF2CH3, R152a, boiling point: −24° C.)
Among the above fluorinated hydrocarbons, a ternary mixed refrigerant of R32/R125/R134a in which the proportions thereof are 23/25/52 wt % (R407C), a ternary mixed refrigerant of R125/143a/R134a in which the proportions thereof are 44/52/4 wt % (R404A), etc., have been proposed, and R404A is currently widely used as a refrigerant for freezing and refrigerated storage (for example, Patent Literature 1 and 2).
However, the global warming potential (GWP) of R404A is as high as 3922, which is equal to or higher than that of CHClF2 (R22), which is a chlorine-containing fluorinated hydrocarbon. There is thus a desire to develop, as alternative refrigerants for R404A, a refrigerant and refrigerant composition that have, for example, a non-flammability similar to that of R404A, a refrigerating capacity that can replace that of R404A, a ratio of refrigerating capacity to power consumed in a refrigeration cycle (coefficient of performance (COP)) that is equal or superior to that of R404A, and a lower GWP than that of R404A.